1901.] NATURAL SCIENCES OF PHILADELPHIA. 11£> 



ON SOME POINTS IN THE PHYLOGENY OF THE PRIMATES. 

 BY ARTHUR ERWIN BROWN. 



The suggestions liere offered, as to the possible orieriu of certairt 

 structural resemblances noted between anthropomorpha and one of 

 the family groups of existing lemurs, have resulted as a by- 

 product from a study of the interrelations of the Primates, under- 

 taken with a different purpose; they are put forth simply as a con- 

 tribution to the sum total of possibilities which, upon final sifting, 

 shall some day determine the exact degree and manner of the rela- 

 tionship between men, apes and monkeys, and not in any sense as a 

 demonstrated conclusion — for the reaching of which more de- 

 tailed knowledge of the early Tertiary mammals is required. 



In accounting for the later stages in the phylogeny of man^ 

 three hypotheses are to be considered. 



The view of Darwin,^ now held by a majority of systematists,. 

 is that the anthropomorpha (here used to include man and the 

 higher apes) branched ofl from the main stem of monkeys after 

 its divergence from the lemurs. 



In 1860, Gratiolet' was led by a study of brain chai'acters aloue^ 

 to the conclusion that each genus of anthropoid apes Avas descended 

 from an existing genus of monkeys; thus he derived Gorilla from 

 Cynocephalus ; Anthropopithecus from Macacus; Simia and Hylo- 

 bates from Semnopitheeu.<. This view has received little support 

 and the facts now known show its complete untenability. 



Lastly, Prof. E. D. Cope^ has suggested a common origin for the 

 anthropomorpha directly from the Eocene lemuroids, indepen- 

 dently of the line by which the monkeys came from the same 

 stock, being led to this conclusion by a study of the tendency in 

 certain races of men to the production of tritubercular upper 

 molars, which tendency he interprets as reversion, or retrogressive 



^ Descent of Man, Chapter VI. 

 ^ ComptesBendus, 1860, p. 801, 



^Journal of Morphology, 1888, p. 21, and Primary Factors of Organic 

 Evolution, p. 154 (1896).' 



